A smart card is a plastic card about the size of a credit card that contains an embedded microchip that can store data and enable phone calls, payments, and other applications. It holds more information than standard credit cards and some can be reloaded for reuse. Important early patents for smart cards were filed in the late 1960s and 1970s. Smart cards provide identification, authentication, data storage and allow for multiple applications. They are used for payment, identification, access control, and more. While offering security and reusability, smart cards also present risks if lost or stolen.